Correlations and fluctuations of stress and velocity in suspensions of swimming microorganisms
Correlations and fluctuations of stress and velocity in suspensions of swimming microorganisms
复制标题
游动微生物悬浮液中应力和速度的相关性和波动
DOI：
10.1063/1.3670420
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发表时间：
2011
影响因子：
4.6
通讯作者：
M. Graham
中科院分区：
文献类型：
--
作者：
Patrick T. Underhill;M. Graham
被驱离平衡的活动系统可以产生不受涨落耗散定理限制的长程关联和大涨落。我们在这里考虑水动力相互作用的游泳微生物悬浮液中的波动和相互关系。将生物模拟为Stokes流中的力偶极子，并考虑其取向动力学的游动-翻滚和旋转扩散模型，可以推导出长波极限内应力涨落的封闭形式的结果。这两个模型都得到了洛伦兹分布，与一些实验数据相一致。这些涨落不受涨落耗散定理的限制，通过比较涨落和悬浮液的粘度明确地证实了这一点。除了悬浮液中的应力波动，我们还检查了有机体之间的相关性。由于水动力相互作用，两个生物体的速度是相互关联的。
Active systems, which are driven out of equilibrium, can produce long range correlations and large fluctuations that are not restricted by the fluctuation-dissipation theorem. We consider here the fluctuations and correlations in suspensions of swimming microorganisms that interact hydrodynamically. Modeling the organisms as force dipoles in Stokes flow and considering run-and-tumble and rotational diffusion models of their orientational dynamics allow derivation of closed form results for the stress fluctuations in the long-wave limit. Both of these models lead to Lorentzian distributions, in agreement with some experimental data. These fluctuations are not restricted by the fluctuation-dissipation theorem, as is explicitly verified by comparing the fluctuations with the viscosity of the suspension. In addition to the stress fluctuations in the suspension, we examine correlations between the organisms. Because of the hydrodynamic interactions, the velocities of two organisms are correlated even if the po...
影响因子：
15
作者：
Yu H;Jo K;Kounovsky KL;de Pablo JJ;Schwartz DC
通讯作者：
Schwartz DC